In U.S. Pat. No. 3,497,169 (1970), a tractor operated trailer hitch is disclosed including a vertical strut and a diagonal strut which support a hitch head or fifth wheel which holds a highway trailer kingpin in place on a railway flat car. The hitch is held in the upright position by a pair of movable hook-shaped locking lugs located in either side of the diagonal strut and pivotably mounted about a pin located at the base of the diagonal strut. The hitch is moved to upright position by a tractor which lifts the vertical strut of the hitch to upright position. In upright position the movable locking lugs engage fixed locking lugs located on either side of the hitch.
To move the hitch to a retracted position, a tractor engages a bumper bar which activates a linkage extending through the diagonal strut which lifts the movable locking lugs from the fixed locking lugs and allows the hitch to assume the retracted position.
However, if the tractor impacts the bumper bar with too great a force, the linkage extending through the diagonal strut and the linkage in the head can be damaged.